Antenna



FIG. 1 is a top plan view of an antenna showing my new design;

FIG. 2 is a front side elevational view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is top perspective view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is another front side elevational view thereof.

The broken lines showing a base in FIGS. 1-4 are for the purpose of illustrating environment, and form no part of the claimed design. 

CLAIM The ornamental design for an antenna, as shown and described. 